/**
 * @file
 * Ethernet Interface Skeleton
 *
 */

/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Adam Dunkels <adam@sics.se>
 *
 */

/*
 * This file is a skeleton for developing Ethernet network interface
 * drivers for lwIP. Add code to the low_level functions and do a
 * search-and-replace for the word "ethernetif" to replace it with
 * something that better describes your network interface.
 */

#include "ethernetif.h"
#include "lwip/def.h"
#include "lwip/err.h"
#include "lwip/mem.h"
#include "lwip/opt.h"
#include "lwip/pbuf.h"
#include "lwip/sys.h"
#include "netif/etharp.h"

#include "lwip/timeouts.h"
#include "stm32f4x7_eth.h"
#include <string.h>

#include "FreeRTOS.h"
#include "semphr.h"
#include "task.h"
#define netifMTU                       (1500)
#define netifINTERFACE_TASK_STACK_SIZE (256)
#define netifINTERFACE_TASK_PRIORITY   (configMAX_PRIORITIES - 1)
#define netifGUARD_BLOCK_TIME          (250)
/* The time to block waiting for input. */
#define emacBLOCK_TIME_WAITING_FOR_INPUT ((TickType_t)100)

/* Define those to better describe your network interface. */
#define IFNAME0 's'
#define IFNAME1 't'

#define ETH_DMARxDesc_FrameLengthShift 16
// #define  ETH_ERROR              ((u32)0)
// #define  ETH_SUCCESS            ((u32)1)

static struct netif *s_pxNetIf = NULL;
SemaphoreHandle_t s_xSemaphore = NULL;

// #define ETH_RXBUFNB        4
// #define ETH_TXBUFNB        2

///* Ethernet Rx & Tx DMA Descriptors */
extern ETH_DMADESCTypeDef DMARxDscrTab[ETH_RXBUFNB], DMATxDscrTab[ETH_TXBUFNB];

/* Ethernet Receive buffers  */
extern uint8_t Rx_Buff[ETH_RXBUFNB][ETH_MAX_PACKET_SIZE];

/* Ethernet Transmit buffers */
extern uint8_t Tx_Buff[ETH_TXBUFNB][ETH_MAX_PACKET_SIZE];

/* Global pointers to track current transmit and receive descriptors */
extern ETH_DMADESCTypeDef *DMATxDescToSet;
extern ETH_DMADESCTypeDef *DMARxDescToGet;

// typedef struct
//{
//	u32 length;
//	u32 buffer;
//	ETH_DMADESCTypeDef *descriptor;
// }FrameTypeDef;

FrameTypeDef ETH_RxPkt_ChainMode(void);
u32 ETH_GetCurrentTxBuffer(void);
u32 ETH_TxPkt_ChainMode(u16 FrameLength);

static void ethernetif_input(void *pvParameters);
static void arp_timer(void *arg);

/**
 * In this function, the hardware should be initialized.
 * Called from ethernetif_init().
 *
 * @param netif the already initialized lwip network interface structure
 *        for this ethernetif
 */
static void low_level_init(struct netif *netif)
{
  uint32_t i;

  struct ethernetif *ethernetif = netif->state;

  /* set netif MAC hardware address length */
  //netif->hwaddr_len = ETHARP_HWADDR_LEN;

  /* set netif MAC hardware address */
  // move to init
  // netif->hwaddr[0] = 0x02;
  // netif->hwaddr[1] = 0;
  // netif->hwaddr[2] = 0;
  // netif->hwaddr[3] = 0;
  // netif->hwaddr[4] = 0;
  // netif->hwaddr[5] = 0;

  /* set netif maximum transfer unit */
  netif->mtu = 1500;

  /* Accept broadcast address and ARP traffic */
  netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP;

  s_pxNetIf = netif;

  /* create binary semaphore used for informing ethernetif of frame reception */
  if (s_xSemaphore == NULL)
  {
    s_xSemaphore = xSemaphoreCreateCounting(20, 0);
  }

  /* initialize MAC address in ethernet MAC */
  ETH_MACAddressConfig(ETH_MAC_Address0, netif->hwaddr);

  /* Initialize Tx Descriptors list: Chain Mode */
  ETH_DMATxDescChainInit(DMATxDscrTab, &Tx_Buff[0][0], ETH_TXBUFNB);
  /* Initialize Rx Descriptors list: Chain Mode  */
  ETH_DMARxDescChainInit(DMARxDscrTab, &Rx_Buff[0][0], ETH_RXBUFNB);

  /* Enable Ethernet Rx interrrupt */
  {
    for (i = 0; i < ETH_RXBUFNB; i++)
    {
      ETH_DMARxDescReceiveITConfig(&DMARxDscrTab[i], ENABLE);
    }
  }

#ifdef CHECKSUM_BY_HARDWARE
  /* Enable the checksum insertion for the Tx frames */
  {
    for (i = 0; i < ETH_TXBUFNB; i++)
    {
      ETH_DMATxDescChecksumInsertionConfig(&DMATxDscrTab[i], ETH_DMATxDesc_ChecksumTCPUDPICMPFull);
    }
  }
#endif

  /* create the task that handles the ETH_MAC */
  xTaskCreate(ethernetif_input, (const char *)"Eth_if", netifINTERFACE_TASK_STACK_SIZE, NULL,
              netifINTERFACE_TASK_PRIORITY, NULL);

  /* Enable MAC and DMA transmission and reception */
  ETH_Start();
}

/**
 * This function should do the actual transmission of the packet. The packet is
 * contained in the pbuf that is passed to the function. This pbuf
 * might be chained.
 *
 * @param netif the lwip network interface structure for this ethernetif
 * @param p the MAC packet to send (e.g. IP packet including MAC addresses and type)
 * @return ERR_OK if the packet could be sent
 *         an err_t value if the packet couldn't be sent
 *
 * @note Returning ERR_MEM here if a DMA queue of your MAC is full can lead to
 *       strange results. You might consider waiting for space in the DMA queue
 *       to become availale since the stack doesn't retry to send a packet
 *       dropped because of memory failure (except for the TCP timers).
 */

static err_t low_level_output(struct netif *netif, struct pbuf *p)
{
  static SemaphoreHandle_t xTxSemaphore = NULL;
  struct pbuf *q;
  uint32_t l = 0;
  u8 *buffer;

  if (xTxSemaphore == NULL)
  {
    vSemaphoreCreateBinary(xTxSemaphore);
  }

  if (xSemaphoreTake(xTxSemaphore, netifGUARD_BLOCK_TIME))
  {
    buffer = (u8 *)(ETH_GetCurrentTxBuffer());
    for (q = p; q != NULL; q = q->next)
    {
      memcpy((u8_t *)&buffer[l], q->payload, q->len);
      l = l + q->len;
    }
    ETH_TxPkt_ChainMode(l);
    xSemaphoreGive(xTxSemaphore);
  }

  return ERR_OK;
}

/**
 * Should allocate a pbuf and transfer the bytes of the incoming
 * packet from the interface into the pbuf.
 *
 * @param netif the lwip network interface structure for this ethernetif
 * @return a pbuf filled with the received packet (including MAC header)
 *         NULL on memory error
 */
static struct pbuf *low_level_input(struct netif *netif)
{
  struct pbuf *p, *q;
  u16_t len;
  int l = 0;
  FrameTypeDef frame;
  u8 *buffer;

  p = NULL;
  frame = ETH_RxPkt_ChainMode();
  /* Obtain the size of the packet and put it into the "len"
     variable. */
  len = frame.length;

  buffer = (u8 *)frame.buffer;

  /* We allocate a pbuf chain of pbufs from the pool. */
  p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);

  if (p != NULL)
  {
    for (q = p; q != NULL; q = q->next)
    {
      memcpy((u8_t *)q->payload, (u8_t *)&buffer[l], q->len);
      l = l + q->len;
    }
  }

  /* Set Own bit of the Rx descriptor Status: gives the buffer back to ETHERNET DMA */
  frame.descriptor->Status = ETH_DMARxDesc_OWN;

  /* When Rx Buffer unavailable flag is set: clear it and resume reception */
  if ((ETH->DMASR & ETH_DMASR_RBUS) != (u32)RESET)
  {
    /* Clear RBUS ETHERNET DMA flag */
    ETH->DMASR = ETH_DMASR_RBUS;
    /* Resume DMA reception */
    ETH->DMARPDR = 0;
  }

  return p;
}

/**
 * This function is the ethernetif_input task, it is processed when a packet
 * is ready to be read from the interface. It uses the function low_level_input()
 * that should handle the actual reception of bytes from the network
 * interface. Then the type of the received packet is determined and
 * the appropriate input function is called.
 *
 * @param netif the lwip network interface structure for this ethernetif
 */
void ethernetif_input(void *pvParameters)
{
  struct pbuf *p;

  for (;;)
  {
    if (xSemaphoreTake(s_xSemaphore, emacBLOCK_TIME_WAITING_FOR_INPUT) == pdTRUE)
    {
      p = low_level_input(s_pxNetIf);
    }
    else
    {
      p = low_level_input(s_pxNetIf);
    }
    if (p != NULL)
    {
      if (ERR_OK != s_pxNetIf->input(p, s_pxNetIf))
      {
        pbuf_free(p);
        p = NULL;
      }
    }
    // vTaskDelay(10);
  }
}

/**
 * Should be called at the beginning of the program to set up the
 * network interface. It calls the function low_level_init() to do the
 * actual setup of the hardware.
 *
 * This function should be passed as a parameter to netif_add().
 *
 * @param netif the lwip network interface structure for this ethernetif
 * @return ERR_OK if the loopif is initialized
 *         ERR_MEM if private data couldn't be allocated
 *         any other err_t on error
 */
err_t ethernetif_init(struct netif *netif)
{
  LWIP_ASSERT("netif != NULL", (netif != NULL));

#if LWIP_NETIF_HOSTNAME
  /* Initialize interface hostname */
  netif->hostname = "DGU_eth1";
#endif /* LWIP_NETIF_HOSTNAME */

  netif->name[0] = IFNAME0;
  netif->name[1] = IFNAME1;

  netif->output = etharp_output;
  netif->linkoutput = low_level_output;

  /* initialize the hardware */
  low_level_init(netif);

  etharp_init();
  sys_timeout(ARP_TMR_INTERVAL, arp_timer, NULL);

  return ERR_OK;
}

static void arp_timer(void *arg)
{
  etharp_tmr();
  sys_timeout(ARP_TMR_INTERVAL, arp_timer, NULL);
}

/*******************************************************************************
 * Function Name  : ETH_RxPkt_ChainMode
 * Description    : Receives a packet.
 * Input          : None
 * Output         : None
 * Return         : frame: farme size and location
 *******************************************************************************/
FrameTypeDef ETH_RxPkt_ChainMode(void)
{
  u32 framelength = 0;
  FrameTypeDef frame = {0, 0};

  /* Check if the descriptor is owned by the ETHERNET DMA (when set) or CPU (when reset) */
  if ((DMARxDescToGet->Status & ETH_DMARxDesc_OWN) != (u32)RESET)
  {
    frame.length = ETH_ERROR;

    if ((ETH->DMASR & ETH_DMASR_RBUS) != (u32)RESET)
    {
      /* Clear RBUS ETHERNET DMA flag */
      ETH->DMASR = ETH_DMASR_RBUS;
      /* Resume DMA reception */
      ETH->DMARPDR = 0;
    }

    /* Return error: OWN bit set */
    return frame;
  }

  if (((DMARxDescToGet->Status & ETH_DMARxDesc_ES) == (u32)RESET) &&
      ((DMARxDescToGet->Status & ETH_DMARxDesc_LS) != (u32)RESET) &&
      ((DMARxDescToGet->Status & ETH_DMARxDesc_FS) != (u32)RESET))
  {
    /* Get the Frame Length of the received packet: substruct 4 bytes of the CRC */
    framelength = ((DMARxDescToGet->Status & ETH_DMARxDesc_FL) >> ETH_DMARxDesc_FrameLengthShift) - 4;

    /* Get the addrees of the actual buffer */
    frame.buffer = DMARxDescToGet->Buffer1Addr;
  }
  else
  {
    /* Return ERROR */
    framelength = ETH_ERROR;
  }

  frame.length = framelength;

  frame.descriptor = DMARxDescToGet;

  /* Update the ETHERNET DMA global Rx descriptor with next Rx decriptor */
  /* Chained Mode */
  /* Selects the next DMA Rx descriptor list for next buffer to read */
  DMARxDescToGet = (ETH_DMADESCTypeDef *)(DMARxDescToGet->Buffer2NextDescAddr);

  /* Return Frame */
  return (frame);
}

/*******************************************************************************
 * Function Name  : ETH_TxPkt_ChainMode
 * Description    : Transmits a packet, from application buffer, pointed by ppkt.
 * Input          : - FrameLength: Tx Packet size.
 * Output         : None
 * Return         : ETH_ERROR: in case of Tx desc owned by DMA
 *                  ETH_SUCCESS: for correct transmission
 *******************************************************************************/
u32 ETH_TxPkt_ChainMode(u16 FrameLength)
{
  /* Check if the descriptor is owned by the ETHERNET DMA (when set) or CPU (when reset) */
  if ((DMATxDescToSet->Status & ETH_DMATxDesc_OWN) != (u32)RESET)
  {
    /* Return ERROR: OWN bit set */
    return ETH_ERROR;
  }

  /* Setting the Frame Length: bits[12:0] */
  DMATxDescToSet->ControlBufferSize = (FrameLength & ETH_DMATxDesc_TBS1);

  /* Setting the last segment and first segment bits (in this case a frame is transmitted in one descriptor) */
  DMATxDescToSet->Status |= ETH_DMATxDesc_LS | ETH_DMATxDesc_FS;

  /* Set Own bit of the Tx descriptor Status: gives the buffer back to ETHERNET DMA */
  DMATxDescToSet->Status |= ETH_DMATxDesc_OWN;

  /* When Tx Buffer unavailable flag is set: clear it and resume transmission */
  if ((ETH->DMASR & ETH_DMASR_TBUS) != (u32)RESET)
  {
    /* Clear TBUS ETHERNET DMA flag */
    ETH->DMASR = ETH_DMASR_TBUS;
    /* Resume DMA transmission*/
    ETH->DMATPDR = 0;
  }

  /* Update the ETHERNET DMA global Tx descriptor with next Tx decriptor */
  /* Chained Mode */
  /* Selects the next DMA Tx descriptor list for next buffer to send */
  DMATxDescToSet = (ETH_DMADESCTypeDef *)(DMATxDescToSet->Buffer2NextDescAddr);

  /* Return SUCCESS */
  return ETH_SUCCESS;
}

/*******************************************************************************
 * Function Name  : ETH_GetCurrentTxBuffer
 * Description    : Return the address of the buffer pointed by the current descritor.
 * Input          : None
 * Output         : None
 * Return         : Buffer address
 *******************************************************************************/
u32 ETH_GetCurrentTxBuffer(void)
{
  /* Return Buffer address */
  return (DMATxDescToSet->Buffer1Addr);
}
